In order to efficiently use electric power, it is preferable that the supply and demand of power match each other. In general, the amount of supplied power is determined to match predicted power demand.
In this regard, Patent Document 1 discloses a technique in which a management device is mounted in a manufacturing facility or the like of a power-demander and a target value of the amount of used power is transmitted to the management device.
Further, Patent Document 2 discloses a technique in which batteries of an electric vehicle are considered as dispersive power resources and the plural power resources are controlled according to a predetermined schedule.
Meanwhile, in recent years, power generation using renewable energy such as solar cell power generation or wind power generation has increased. In such a power generation method, it is difficult to control the amount of generated power. In this case, with a general method, it is difficult to achieve the supply-demand balance of power.
In this regard, Non-Patent Document 1 discloses a technique that reduces an output variation in solar cell power generation using an electric vehicle. Further, Non-Patent Document 2 discloses the following technique. First, charging time zones of electric vehicles and a target total charging power are set with respect to a power-generation and demand schedule made in consideration of surplus power that is predicted in advance. Then, in an operation of the scheduled day, the order of priority based on the necessity of charging is assigned to plural electric vehicles, and the number of electric vehicles necessary for achieving the target total charging power are selected.